A linear solar concentrator produces electricity by using a mirror to focus sunlight on a fluid filled tube known as a heat collection element. The fluid inside the element is then used as a heat source for steam generation in a conventional steam turbine power plant. This study examined the effect of adding microstructures to the surface of a heat collection element to improve system efficiency. Four test pieces, one with a smooth surface and three with a microstructured surface were compared experimentally for a given energy input and five different flow rates ranging from 0.84 cm(3)/s to 2.5 cm(3)/s. Over the entire range of flow rates the microchannel test piece absorbed no less than 1.29 times the energy of the smooth test piece. (C) 2011 Elsevier Ltd. All rights reserved.